Introduction

In this brief post, I will share the solution to a recurring issue within our environment where a Microsoft 365 add-in (also known as an integrated app) deployed from the Microsoft 365 admin center was frequently missing in Outlook.

The custom integrated app in question is deployed by uploading an add-in manifest to the Microsoft 365 admin center. From there, it is assigned to either the entire organization or a selected group of users.

In this instance, the add-in manifest was updated with a new version. However, the changes were not properly reflected in Outlook for our users.

It appears that Outlook does not effectively clear cached content from the add-in. Therefore, it is recommended to manually clear this cache if any issues arise.

The solution

The solution to this issue is documented in the official Microsoft documentation: Clear the Office cache – Office Add-ins.

Based on this guidance, I developed a PowerShell script that can be deployed to affected computers to clear the cache.

PowerShell

You can find the script in my GitHub repository here: PowerShell/Clear-Cache-Integrated-M365-Apps.ps1 at master · imabdk/PowerShell

The script accepts one parameter with 2 possible values, depending on whether you want to clear the cache for Outlook or any of the other Office applications.

• .\Clear-Cache-Integrated-M365-Apps.ps1 -OfficeApp “Outlook”
• .\Clear-Cache-Integrated-M365-Apps.ps1 -OfficeApp “Other”

Deploy the script

Use your preferred deployment method to distribute the script. I prefer using Configuration Manager, but the script can also be deployed using Intune.

Below is a snip from the program running the script in my environment: